On Tue, Mar 05, 2013 at 04:48:43PM +0100, Maarten Deen wrote: > On 2013-03-05 16:22, Jochen Topf wrote: > >On Tue, Mar 05, 2013 at 09:57:31AM -0500, Serge Wroclawski wrote: > >>I worked on an Ozone monitoring instrument briefly in my career, and > >>my understanding is that the polar ice caps change often. > > > >No, they don't change all that much. Of course they change a > >little bit all the > >time, the ice cap moves about 10m a year at the South Pole for > >instance, and > >sometimes large icebergs break off from the shelf-ice, but for the > >resolution > >we are talking about here, the resolution interesting for OSM, > >they are > >basically static. > > > >>Are you proposing that we change them every N months? > > > >No. > > > >>If so, I think we have better solutions at our disposal than > >>trying to > >>delete/reimport huge areas like this. > > > >This is a misunderstanding. The reason the old data is bad is not that > >Antarctica changed so much between then and now. I don't know why > >the old > >data is so bad, maybe it is because satellite images etc. have > >improved > >since then so better data could be derived. > > In the beginning the coastline was very coarse. So much that the > then current algorithm of generating tiles (especially for T@H) > sometimes didn't find data to work with (because nodes were so far > apart) so it rendered an empty tile. > I did a lot of work making it more precise according to the aerials > available. I haven't checked in recent years how it correlates to > current aerials.
Bing has rather good coverage now which also fits well to the data we are proposing to import. It is pretty easy to take a look youself. Download current Geofabrik Antarctica extract, download proposed import (http://www.imagico.de/files/moa_proc.osm.bz2), load both into JOSM in different layers, add Bing images. Look around and compare. Jochen -- Jochen Topf [email protected] http://www.remote.org/jochen/ +49-721-388298 _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
